Requirements of Immediate Denture, 196
Indications of Immediate Denture, 197
Contraindications of Immediate Denture, 197
Advantages of Immediate Dentures, 197
Disadvantages of Immediate Dentures, 197
Diagnosis and Treatment Planning of Immediate
Fabrication of Immediate Denture, 198
Pathophysiology in Combination
Indications for Single Complete Denture, 203
Materials of Tooth Form Opposing Natural
Techniques to Modify Natural Teeth, 206
Immediate dentures and single complete dentures are fabricated
depending on the type of clinical situation. In immediate dentures, the
prosthesis is inserted immediately after extraction of remaining teeth,
whereas in case of single complete dentures, the position, size and
location of the remaining natural teeth determine the type, tooth form
and occlusion of the dentures.
Immediate denture is defined as ‘any removable dental prosthesis
fabricated for placement immediately following the removal of a natural
Requirements of immediate denture
• It should restore masticatory efficiency within limits.
• It should preserve aesthetics.
• It should preserve the remaining tissues.
• It should harmonize with functions of speech, deglutition and
Indications of immediate denture
• It is indicated in any healthy dentulous or partially edentulous
patient whose remaining natural teeth need to be extracted due to
caries, periodontal reasons or trauma.
• It is indicated in a cooperative patient with good dexterity and
Contraindications of immediate denture
• A patient with poor surgical risks, such as cardiac disorders,
glandular disorders or blood dyscrasias
• A patient with mental illness
• A patient with limited dexterity
Advantages of immediate dentures
• Maintenance of the vertical dimension – if the posterior teeth are
present, it is likely that the vertical dimension is correct.
• Natural teeth serve as an excellent guide during teeth selection and
• It avoids the embarrassing edentulous period.
• Postoperative pain is less because the extraction site is protected.
• There are less chances of residual ridge resorption.
• The patient’s function of speech, deglutition and mastication are not
• It acts as a bandage or splint to control bleeding and food lodgement
• It aids in rapid healing of surgical site.
• It results in increased patient acceptance due to the presence of teeth at
Disadvantages of immediate dentures
• There is no scope of anterior try-in.
• It is expensive, because the immediate dentures will require frequent
relining to meet the rapid changes in the tissues.
• Potentially, it gives less retention because of arbitrary scrapping of
the cast to fabricate the prosthesis.
• Need to reline is frequent as the resorption of the bone and the
shrinkage of the tissues are faster and greater.
• Do not replace the stimulation provided by the natural teeth to the
There are two types of immediate dentures, which are:
(i) Conventional immediate denture: After healing, the immediate
denture is either refitted or relined to serve as a long-term
(ii) Interim immediate denture: It is worn by the patient only during the
healing period. It is then replaced by a new prosthesis.
Diagnosis and treatment planning of immediate
Diagnosis is defined as the determination of the nature, location and cause
Diagnostic procedure starts by reviewing the medical and dental
history of the patient, intraoral and extraoral examinations of the soft
and hard tissues, evaluation of the patient’s mental attitude and
Medical history and past dental history of the patient are of utmost
importance in evaluating the prognosis for the immediate dentures.
Some of the systemic conditions which can affect the basal seat are:
• Cardiovascular and cerebrovascular diseases – these present a
problem of poor clotting mechanism
• Mucosal disorders such as desquamative stomatitis
• Keratosis, hyperkeratosis and dyskeratosis can result from
deficiency of vitamins A and B
• Dermatological disease, such as psoriasis, pemphigus or erosive
• Collagen disorders such as lupus erythematosus
• Osteoporosis resulting from bone matrix defect
During the extraoral examination, facial form, facial symmetry,
facial profile and temporomandibular joint (TMJ) are evaluated. It is
followed by complete clinical examination of the hard and soft tissues,
which also includes assessing the periodontal condition of the
remaining teeth. It is supplemented by full mouth radiographic series
(IOPA and bitewing) which are helpful in evaluating the extent of the
bone loss due to periodontal disease.
Local factors which are of significance in complete immediate
• Periodontal status of the remaining teeth to be extracted
• Location of the teeth in the arch
• Presence and severity of soft and hard tissue undercuts
• Condition of the bone adjacent to the remaining teeth
• Lack of muscular coordination
Mounted diagnostic casts are an important aid in evaluating the
position of the teeth, jaw relationship and any occlusal plane
discrepancies. These also help in analysing the tissue undercuts.
Position of the lip line and amount of tooth exposure in function are
clinically evaluated. Location of the posterior limit should be
tentatively marked on the cast. Any requirements of occlusal
corrections on the opposing teeth are planned on the cast during this
A patient’s psychological status and mental attitude should be
assessed during the diagnosis and treatment planning phase. The
patient’s expectations are discussed and the patient should be
educated from the first visit to the completion of the treatment.
A treatment plan is formulated based on the diagnostic information
of the patient. When a treatment plan is made for immediate complete
dentures, either both the maxillary and mandibular arches are
restored together or either of the arches is restored. It should be
preferred to restore the single arch with immediate complete denture
and after its stabilization, the opposing arch should be treated.
Fabrication of immediate denture
The procedure for fabrication of immediate dentures is discussed
• Mouth preparation for immediate complete dentures starts at least 6
weeks before making the final impression.
• It is recommended to remove all the posterior teeth except unilateral
or bilateral bicuspids to maintain the vertical height.
• Removal of posterior teeth should be 4–6 weeks before the final
impression to ensure establishment of posterior borders for the
• A single stage in which all the teeth are removed in one visit and
immediate dentures inserted in the same visit is recommended for
patients having very depleted oral condition.
• Primary impression is made with irreversible hydrocolloid using a
• Impression is poured with stone to form a diagnostic cast.
• Diagnostic casts are used to fabricate custom trays.
• Custom trays are fabricated using autopolymerizing resin.
• The remaining teeth are covered with two thickness of baseplate
wax. The wax acts as a spacer.
• Any undercut area is blocked with wax before custom tray
• There are two techniques of making final impression, which are as
1. In the first technique (single impression
technique), a single custom tray is fabricated by
covering the entire denture border area.
• Border moulding is done using green stick
• Custom tray is perforated to ensure flow of excess
material and increase the retention of the material
• Tray adhesive is applied over the impression surface.
and hard tissues with accuracy and facilitates
removal because of its elasticity.
2. In the second technique (dual impression
technique), custom tray extends onto the
• The tray is moulded with a green stick compound.
• Impression is made of the edentulous area using
zinc oxide eugenol impression paste.
• Impression is removed and inspected.
• Impression is replaced and an irreversible
hydrocolloid-loaded tray is placed in the mouth.
• Once the impression material sets, the stock tray is
removed along with the custom tray which is
• Impression is poured with vacuum-mixed dental
stone to obtain the master cast.
• Recording base with wax occlusal rims is fabricated in the
• A facebow record is made to orient the cast on the articulator.
• A tentative occlusal vertical dimension is obtained.
• Centric relation record is made at a slightly increased vertical
dimension using free-flowing medium on the occlusal rim such as
zinc oxide eugenol impression paste.
• Lower cast is mounted using this record.
Teeth selection and arrangement of teeth
• Shape, size and shade of the teeth are selected using the existing
• Appropriate teeth are selected and arranged so as to provide
bilateral posterior contacts in centric relation.
• Posterior try-in is done to verify the centric relation and the vertical
dimension of occlusion (Fig. 12-1).
• Position of the posterior palatal seal is verified and scribed on the
• The anterior teeth are arranged once the satisfactory posterior try-in
• The anterior teeth are trimmed one at a time from the master cast.
• Each tooth is trimmed to the level of gingival margin using a sharp BP
• Denture tooth is positioned in this space.
• In the first method, alternate teeth are removed from the cast and the
• This procedure is repeated for arranging all the anterior teeth.
• This method ensures accurate positioning of the teeth and
maintaining natural appearance.
• In the second method, teeth on the cast are trimmed to a line
corresponding to the depth of the gingival sulcus and are broken off
the cast at their cervical aspect.
• One segment of the cast is trimmed and the teeth are arranged
taking the other segment as a guide.
• Similarly, the other segment is removed and the denture teeth are
• The advantage of this method is that the clinician can ensure that the
complete cast preparation is carried out correctly.
• Wax-up of the denture is done to provide adequate thickness and
proper contour of the denture base.
• After the de-waxing procedure, the cast can be trimmed, if needed
to smoothen the ridge contour.
• The denture is processed using conventional techniques.
• The finished denture is stored in a disinfectant solution and is
thoroughly cleaned before insertion.
• The remaining teeth are removed after adequately anaesthetizing
• Bony spicules or sharp edges are removed with minimal trauma.
• Surgical template is used to evaluate the prepared site.
• After the surgical procedure, the dentures are carefully seated and
• Denture is checked for any overextension.
• Gross occlusal premature contacts are relieved.
• Tissue conditioners can be used, if the impression surface is
• The patient is instructed not to remove the denture for first 24 h.
• The patient is advised proper medication to control pain.
Surgical template is defined as ‘a thin, transparent form duplicating the
tissue surface of a dental prosthesis and used as a guide for surgically
shaping the alveolar process’. (GPT 8th Ed)
Surgical template is used as a guide for shaping the ridge while the
teeth are removed and immediate dentures are inserted.
• This reveals the amount of bone to be removed during surgical
• This is useful when large amount of bone recontouring is essential.
• This is used as a necessary adjunct during contouring of any
• This is useful in removing sharp bony spicules.
• If a small amount of bone needs to be recontoured, the denture can
be relieved using pressure-indicating paste rather than bone
• After the wax elimination procedure and cleansing, the ridge area of
the cast is trimmed to the desired form.
• Impression is made of the trimmed cast with irreversible
• Impression is poured with dental stone.
• An accurately fitting clear resin template is formed over the
duplicate cast using following methods:
(i) Vacuum form method: Clear resin sheet is adapted over the duplicate
cast and a template is formed by means of a vacuum-formed
(ii) Sprinkle-on technique using clear acrylic resin.
(iii) Process a template in clear acrylic resin by making wax pattern for
the template of thickness 2 mm over the cast, flasking and heat
Once the surgical template is fabricated, it is used at the time of
surgical procedure of teeth removal. The template is made to seat over
the surgical site uniformly and completely. In case of any interference
due to bony or soft tissues, it is trimme
Postinsertion care for immediate denture patient is described below.
• The patient is recalled after 24 h of denture wearing.
• Occlusion is checked with articulating paper before removing the
denture. Any premature contact is relieved.
• The dentures are removed and the soft tissue is carefully inspected.
• Any sore spots or overextension is relieved.
• The patient is instructed to rinse mouth gently with a mouthwash.
• Removal and insertion should be done as minimally as possible.
• Liquid diet is prescribed for the patient.
• The patient is recalled after 48 h.
• Steps followed during the first appointment are repeated.
• The patient is instructed to practice warm saline rinses.
• The patient is instructed to wear the denture throughout the night
• Soft diet is prescribed for the patient.
• The patient is recalled after a week.
• Suture removal, if any, is done.
• Occlusion is again checked for any premature contact.
• Tissue surface of the denture is checked using pressure-indicating
• Soft tissues are examined thoroughly for any soreness.
• Tissue conditioners, if used, are replaced.
• The patient is recalled after 3–4 weeks.
• Any specific complaint by the patient is addressed.
• Clinical remounting can be done at this stage to refine the occlusion
• Tissue conditioners, if used, are replaced.
• Number of recall appointments will depend on factors, such as age,
medical health, patient psychology, emotional health and tissue sensitivity.
• The patient is recalled after 4–6 weeks.
• Complete healing of the sockets will take around 6 months.
• The patient is evaluated for fit of the denture.
• If denture is loose, it is relined.
• After 6 months, the denture is either relined or remade.
Combination syndrome occurs when an edentulous maxilla is
opposed by natural mandibular anterior teeth. It is also called anterior
The term combination syndrome was coined by E. Kelly in 1972.
Features of Combination Syndrome (Fig. 12-
• Loss of bone from the anterior portion of the maxillary ridge
• Downward growth of the maxillary tuberosities
• Papillary hyperplasia of the mucosa of the hard palate
• Extrusion of the lower anterior teeth
• Loss of alveolar bone and ridge height, beneath the mandibular
removable partial denture bases
There are six associated changes observed in combination syndrome
(i) Loss of vertical dimension of occlusion
(ii) Occlusal plane discrepancy
(iii) Development of epulis fissuratum
(iv) Anterior spatial repositioning of the mandible
(v) Poor adaptation of the prosthesis
FIGURE 12-2 Schematic diagram showing features of
Pathophysiology in combination syndrome
When the remaining mandibular natural anterior teeth oppose the
maxillary denture, the patient tends to function in protrusive
relationship to masticate. As the anterior portion of the maxillary
ridge is composed primarily of the cancellous bones, it is subjected to
rapid resorption. As the ridge resorps and progresses, the bony ridge
is replaced by the redundant soft tissues, initiating the combination
syndrome and the associated changes.
• With resorption of the maxillary anterior ridge, the denture tends to
tip upward anteriorly and downward posteriorly.
• The labial flange of the denture produces chronic irritation from
overextended labial flange of denture resulting in epulis fissuratum.
• Posterior downward tipping of the maxillary denture results in the
overgrowth of the fibrous tissues covering the maxillary
• The retention and stability of the denture are compromised because of
the changes in the supporting tissues.
• Because of ridge resorption, the angulation of the occlusal plane
changes. The mandible tends to assume more anterior position.
• Supraeruption of the lower anterior teeth takes place because of the
• Loss of posterior support in the mandible results in an increased
anterior occlusal function and a decreased posterior occlusal
Single complete dentures are the making of a maxillary or mandibular
denture as distinguished from a set of complete dentures.
• To achieve an acceptable interocclusal distance
• To achieve a stable jaw relationship with bilateral tooth contacts in
• To achieve stable tooth quadrant relationships providing axially
• To achieve multidirectional freedom of tooth contacts throughout a
small range of mandibular movements
Indications for single complete denture
Single complete denture is desirable when it opposes any one of the
• Combination of fixed restorations and the natural teeth
• A removable partial denture and the natural teeth
• An existing complete denture
Types of Single Complete Dentures
The following are the types of single complete dentures:
• Mandibular denture to oppose natural maxillary teeth
• Single complete maxillary denture opposing natural mandibular
• Complete maxillary denture to oppose a partially edentulous
mandibular arch with fixed prosthesis
• Complete maxillary denture opposing a partially edentulous lower
arch and a removable partial denture
• Single complete denture opposing the existing complete denture
1. Mandibular denture to oppose natural maxillary teeth.
• Completely edentulous mandibular arch usually
occurs because of surgical or accidental trauma.
• Three factors are considered in such patients,
namely, preservation of residual alveolar ridge,
necessity of retaining maxillary teeth and mental
2. Single complete maxillary denture opposing natural mandibular
• It is more common than the mandibular denture.
• The periodontal status of remaining teeth, adequate
freeway space and oral hygiene of the patient are
evaluated during diagnosis and treatment planning
• Whenever possible, balanced occlusion should be
provided in order to enhance the retention and
• Occlusal form of the natural teeth usually
determines the selection of the occlusal form of the
• Because of the angulation of the natural lower teeth,
the upper teeth may not be arranged in the
aesthetically acceptable positions. In order to
encounter this problem, the natural teeth can be
orthodontically repositioned or the clinical crown
of the teeth can be altered by grinding or with
3. Complete maxillary denture to oppose a partially edentulous
mandibular arch with fixed prosthesis
• When maxillary denture opposes a partially
edentulous mandibular arch, in which the missing
teeth are replaced with fixed restoration.
• The occlusal surface material determines the choice of
material for the artificial denture teeth. If the fixed
restorations are made of porcelain, the choice of
material for the denture teeth should be porcelain.
• If the gold restorations are given in the lower arch,
the occlusal surface of the artificial teeth should be
made up of gold or acrylic resin.
4. Complete maxillary denture opposing a partially edentulous lower
arch and a removable partial denture (Fig. 12-4)
• This is one of the most frequently encountered
• The existing partial denture should be critically
evaluated to check the occlusal plane, aesthetics,
arrangement of teeth and the material.
• The condition of the remaining teeth is evaluated.
• If the removable denture is found unsuitable, both
the dentures are simultaneously fabricated.
5. Single complete denture opposing the existing complete denture
• It is important to determine the time at which the
patient is wearing the denture.
FIGURE 12-3 Maxillary complete denture opposing natural
FIGURE 12-4 Single complete maxillary denture opposing
mandibular removable partial denture.
The following queries also need to be considered:
• Whether the existing denture is satisfactory or it needs to be remade
• Was the existing denture inserted immediately after teeth
• Few existing dentures fulfil the ideal requirement of the dentures,
and most of them require either relining or rebasing or remaking of
Materials of tooth form opposing natural
Various tooth form materials that are used to oppose the natural
dentition in single complete denture cases are available. Some of the
commonly used materials are described in Table 12-1.
TYPES OF TOOTH MATERIAL OPPOSING NATURAL TEETH
Techniques to modify natural teeth
Various techniques used to modify the natural teeth prior to the
denture fabrication are reported in literature, some of which are as
1. M.G. Swenson technique (1964)
• Maxillary and mandibular casts are mounted on an
articulator at an acceptable vertical dimension using a
provisional centric relation record.
• On the complete denture cast, the denture base is
fabricated and the teeth are arranged.
• The cast is made to occlude the opposing natural
• If the natural teeth interfere with the denture teeth,
they are marked on the cast with a pencil.
• The natural teeth are then modified using the marked
• After this modification, new diagnostic cast is made
• If more adjustments are required, the procedure is
• Once the occlusal adjustments are sufficient, the
denture teeth are rearranged and are prepared for
• It may require multiple impression and diagnostic
2. A.A. Yurkstas technique (1968)
• A U-shaped metal occlusal template which is convex
• This template is placed on the natural teeth on the
cast and the cusps to be modified are identified and
• The stone cast is adjusted to a more acceptable
occlusal relationship and the areas are identified by
• The cast is then used as a guide to modify the
3. R.W. Bruce technique (1971)
• The lower cast is mounted on the articulator as
• Any occlusal adjustments needed are made on the
• A clear resin template is fabricated over the modified
• The inner surface of the template is coated with
pressure-indicating paste and the template is seated
• The interferences are readily identified on the teeth
• The process is repeated until the clear resin
4. C.O. Boucher et al. technique (1975)
• After the upper and lower casts are mounted on the
programmed articulator, the maxillary artificial
teeth are arranged to obtain the best possible
• If the opposing lower natural teeth interfere in the
balanced occlusal contact, the interfering contact is
identified and is modified on the cast.
• Altered diagnostic cast is used to modify the natural
• Balanced denture is processed.
• The occlusion is refined using an arch-shaped layer
of the softened baseplate wax.
• Any premature contact is identified and the natural
• The procedure is repeated until a harmonious
balanced occlusion is obtained.
FIGURE 12-6 Clear resin template fabricated over modified
• Continuous gum denture is an artificial denture consisting of the
porcelain teeth and tinted porcelain denture base material fused to a
• Immediate dentures should be removed by the dentist after 24 h of
• Thickness of the palatal surface of the maxillary denture should not
Overlay Dentures or Overdentures, 208
Requirements of the Overdenture, 209
Preventive Prosthodontics, 210
Rationale of Retaining Teeth for
Bare Tooth Overdenture (Noncoping
Telescopic Overdenture (Abutments with
Attachment Fixation Overdenture (Abutments
Factors Considered during Attachment
Attachments in Overdenture Design, 215
Resilient Gerber Attachment, 216
Maintenance of Overdentures, 220
Maintenance after Insertion, 220
Overdenture concept emphasizes on the preventive aspect in
prosthodontics in which denture is fabricated over the remaining
natural tooth or root. Preservation of teeth has definite benefits in
reducing rate of resorption, preserving bone and proprioception
Overlay dentures or overdentures
Overlay dentures or overdenture is defined as ‘any removable dental
prosthesis that covers and rests on one or more remaining natural teeth, the
roots of natural teeth, and/or dental implants’. (GPT 8th Ed)
This is also called biologic denture, telescopic denture, onlay denture,
hybrid denture, root-supported denture and superimposed denture.
• It maintains the teeth as part of the residual ridge. The denture rests
over the remaining teeth or root and minimizes its vertical movement.
• It decreases the rate of resorption. Various studies show that
overdenture preserves the alveolar bone and decreases the rate of
• There is preservation of the periodontium along with the teeth. This
increases the manipulative skills of the patient in handling the
• Reduction of the retained teeth to establish a favourable crown–root
Requirements of the overdenture
• Reduction of the crown–root ratio decreases the mobility of the
tooth by decreasing the length of the lever arm and thus reducing
torquing forces on the mobile tooth.
• The basal seat tissues should be well healed and firmly bound to the
underlying bone in order to resist and distribute the functional load
• The denture should be relatively simple to fabricate and maintain.
• The teeth or root utilized for the overdenture should have sound
• The denture should be easily manipulated by the patient.
Classification of Overdentures
• On the basis of method of abutment preparation:
• On the basis of method of retention:
• Submucosal vital root retention
• On the basis of time of fabrication:
• On the basis of type of tooth-supported overdentures:
• Tooth-supported conventional complete
• Tooth-supported immediate complete overdenture
• On the basis of type of design:
• Attachment fixation overdenture
• Overdentures help in preserving the alveolar bone.
• These help in preserving the proprioceptive response by retaining the
neutral teeth and the periodontium.
• These provide a static stable base and greatly improve the stability
and support of the denture, which is not possible with the
• These provide enhanced retention of the prosthesis.
• It is an useful, inexpensive approach to restore function, aesthetics
and comfort in the patients with congenital defects, such as cleft
palate, partial anodontia, microdontia and amelogenesis imperfecta.
• These have excellent patient acceptance.
• It is easy to maintain the optimum health of the periodontium.
• These can be converted easily to conventional complete denture in
case of extraction of the retained tooth/teeth.
• These are of reasonable cost.
• Horizontal and torquing forces are minimized.
• These may require minimum postinsertion appointments.
• Roofless denture or open palate is possible.
• Retained teeth are susceptible to caries.
• Bony undercuts may limit the path of placement of the denture.
• Presence of undercuts may result in denture which may be
overcontoured or undercontoured.
• Increased interocclusal distance is required to accommodate internal
• Aesthetics may be compromised in case of overcontoured or
• The retained teeth are susceptible to periodontal breakdown.
• In a patient with few remaining teeth
• Younger the patient, greater the indication
• In a patient with congenital defects such as cleft lip and palate
• In a patient with high vault palate and sloping ridges
• In a patient with a poorly defined sublingual fold
• In cases when complete denture opposes natural teeth
• In cases where there is extensive bone around the teeth which are to
• In a cooperative and motivated patient
• In case of physically and mentally handicapped patients
• In case of uncooperative and undermotivated patients
• In case of decreased interarch space and severe tissue undercuts
• In a patient with teeth with class III mobility
• In case of soft tissue and bony defects which cannot be corrected by
• In case of vertical fracture or retained root or tooth
• In case of mechanical perforation of the tooth
• In case of horizontal fracture of the root below the bony crest
• In case of broken instrument in the root canal
Preventive prosthodontics emphasizes the importance of any
procedure that can delay or eliminate future prosthodontic problems.
The concept of preventive prosthodontics is highlighted in the
Rationale of retaining teeth for overdentures
Retention of teeth for overdentures offer several advantages both
functionally and biologically. Overdentures should always be
considered in case of loss of alveolar bone support and subsequent
development of unfavourable crown–root ratio. These should be
considered as an alternative to extraction of all the natural teeth.
Sequelae of extracting all the natural teeth are:
• Loss of discrete proprioception
• Progressive loss of alveolar bone
• Transfer of all occlusal forces from the teeth to the oral mucosa
It is logical to preserve the natural tooth or root, as they provide not
only periodontal ligament to support the teeth but also tactile
sensitivity to load, dimensional discrimination, directional sensitivity
Rationale of retaining teeth can be described under three headings:
• Preservation of proprioception
• Occlusal forces in overdentures
Preservation of proprioception
Proprioception is defined as ‘information provided about the position and
movements of the body and its parts by receptors’. (Ramfjord and Ash
The periodontal ligament is richly innervated by these receptors
and the tooth is surrounded by large number of receptors which can
receive mechanical stimulation. Receptors may also be located in the
supporting bone, adjacent periosteum and the mucosa. Retention of
the tooth root preserves the integral component of the sensory feedback
system that programmes the masticatory system throughout the
patient’s life. The neuromuscular function of the masticatory system
depends on the harmony of the sensory feedback and the motor
neuron response at the reflex level.
Retention of the tooth for an overdenture preserves the periodontal
proprioceptors. The afferent input from the periodontal ligament
receptors contains information about the magnitude and direction of the
occlusal forces and the size and the consistency of the food bolus. The
periodontal receptor also protects the teeth against occlusal
R.J. Crum and G.E. Rooney (1975) in their 4-year study compared
alveolar bone loss in patient with mandibular overdenture with
conventional mandibular dentures. It was observed that when
mandibular canines were used for overdentures, the rate of resorption
of bone surrounding the teeth reduced by eight times. The
overdenture patient also exhibited reduced bone loss in the area
immediately posterior to it. This study clearly showed that the use of
overdenture preserved the bone between the canines in both height
With the preservation of bone, the overdenture patient showed
better masticatory ef iciency and reduced loss of overall face height. Several
studies have shown alveolar bone loss after extraction of the natural
teeth and replacement with the conventional complete dentures. Also,
it is shown that the alveolar bone of the anterior mandible resorbs
faster than the anterior maxilla. The use of overdentures clearly
indicates the preservation of the alveolar bone, especially in the area
Occlusal forces in overdentures
F.J. Pacer (1971) found that the overdenture patients could
discriminate measured occlusal forces better at higher levels than the
patient with the conventional dentures. This discrimination was due
to the greater sensory input from the periodontal receptors.
A.H. Fenton (1973) compared the ability of the patient to perceive
thin objects between the occlusal surfaces of the natural dentition,
conventional dentures and overdentures. He found that an
overdenture patient had less occlusal thickness perception than a
patient with the conventional dentures. The natural tooth/root,
therefore, provides better vertical support than the conventional
The factors which are critical in patient selection for overdentures are:
• Periodontal status of the abutment teeth:
• Optimum periodontal health is important for the
longevity of the overdenture treatment.
• Inflammation, periodontal pocket, intrabony defects
or loss of attached gingiva should be eliminated
before beginning the treatment.
• Usually, the overdenture abutment teeth have poor
zone of attached gingiva. This can be corrected by
periodontal surgery using a free gingival graft or
apically repositioned split thickness flap.
• The patient’s caries index should be critically
evaluated before selecting the abutment teeth for
• Healthy clinical crown which is caries-free is desired
• If the tooth is having carious lesion, the extent and
location is evaluated. If the carious tooth can be
restored and an environment can be created so that
the caries incidence is reduced, the particular tooth
• If the patient has high caries index, the overdenture
treatment should be chosen with caution.
• The abutment tooth should be properly prepared,
restored and polished to facilitate plaque control
• The caries-prone tooth can be treated with low
concentration of stannous fluoride or 0.5% acidulated
phosphate fluoride (APF) gel to ensure any further
• The patient should be educated and instructed to
follow home care programme carefully to reduce
• Usually, the teeth selected as abutment for the
overdenture treatment require endodontic therapy
so that sufficient reduction of the clinical crown is
• It should be ensured that the single-rooted or
multirooted teeth are adequately treated
• After endodontic treatment, the tooth should be
observed for 2–4 weeks to rule out any endodontic
• Possibility of fixed or removable partial denture
• If the remaining teeth are capable of supporting the
fixed or removable partial denture, they should be
preferred to the overdenture treatment.
• Age factor is very critical in selecting patient for
• For a young patient with poorly prognosed teeth,
overdenture treatment should be preferred over
• Proper tooth preparation and home care
programme become more critical in such patients.
• Location of the abutment teeth
• Location of the remaining teeth is important to
determine the support of the overdenture and the
• Whenever possible, teeth on both the sides of the
arch should be preserved because this will ensure
better support, better preservation of bone and
maintenance of occlusal vertical dimension.
• Even if single tooth can be preserved, it should be
used as an abutment for overdenture.
• Preservation of teeth become more critical, if the
arch is opposed by natural dentition.
• Sometimes, the cost of the treatment becomes
• It is important to determine the prognosis of the
treatment carefully against the cost of the
The basic overdenture designs:
• Attachment fixation overdenture
Bare tooth overdenture (noncoping abutments)
These overdentures are directly placed over the crownless,
endodontically treated roots, either as an interim step in fabrication or
as a final prosthesis (Fig. 13-1).
FIGURE 13-1 Diagram showing bare tooth overdenture.
• Roots used for support and preserve bone
• It provides only stability without retention.
• Roots are not connected to rigid prosthesis and thus are not
• Exposed dentin is susceptible to caries.
Telescopic overdenture (abutments with copings)
Roots are restored with a cast restorations (primary coping) such that
the prosthesis contacts directly with the denture acrylic or with metal
coping (secondary coping) (Fig. 13-2).
FIGURE 13-2 Diagram showing telescopic overdenture.
• This overdenture retains roots and conserves bone.
• Abutments teeth provide support (often retention) for more stable
• It preserves proprioception.
• It has greater patient acceptance.
• It allows easy modification.
• Auxiliary retention devices can be added later on.
• It is cheaper than the attachment fixation overdenture.
• Retention is fixed and not variable.
• Overdenture can be bulky and less aesthetic than attachment
• Short copings provide minimal retention.
• Long or medium copings may provide inadequate retention.
• Retention is dependant on friction alone, which is not reliable.
• Long or medium copings cannot be used when the interocclusal
Attachment fixation overdenture (abutments with
This type of overdenture may connect to the copings with studs or
other form of attachment such as bar and rider systems. The patient
experiences increased comfort, function and aesthetics as the results
closely approximate that obtained with fixed partial denture or
precision partial denture prosthetics (Fig. 13-3).
FIGURE 13-3 Diagram showing attachment fixation
• Retained roots preserve alveolar bone.
• Coping coverage is indicated for caries control.
• Weaker abutments may be splinted.
• Retention can be adjusted and controlled.
• Better patient acceptance and comfort.
• Better distribution of forces between the abutment and the tissues.
• Attachment fixation overdenture is costly in comparison to
conventional telescopic overdenture.
• It is dif icult to fabricate.
• It is dif icult to maintain.
• Some attachments are bulky and may cause aesthetic and occlusal
• It is difficult to use in a patient with limited dexterity.
Types of Overdenture Attachments
Classification of overdenture attachments on the basis of shape,
design and primary area of their use:
A) Intracoronal – radicular attachments such as Zest, Ginta, etc.
B) Bar attachments – joints, units
Factors considered during attachment selection
• Location of stronger abutment
• Type, i.e. either tooth-supported or tooth-tissue supported
Attachments in overdenture design
There are wide variety of attachments which are used for overdenture
prosthesis. Most of these attachments are named after the inventor,
e.g. Dalla Bona, Zest, Gerber and Dolder. Most of these attachments
are either resilient or nonresilient. A resilient attachment reduces the
vertical and lateral forces on the abutments by distributing the
masticatory load mostly to the tissues. This is accomplished by
creating a gap of 0.5–1 mm between the overdenture and the metal
substructure. Resilient attachments are indicated for tooth-tissue
supported cases. A nonresilient attachment does not permit any vertical
movement during function. If the prosthesis is totally tooth supported,
the abutment teeth should bear the entire load. Attachments can be
1. Extracoronal attachment is defined as ‘any prefabricated attachment
for support and retention of a removable dental prosthesis. The male and
female components are positioned outside the normal contour of the abutment
For example: Studs (Gerber, Dalla Bona, Rotherman,
etc.), bar, auxiliary attachments
2. Intracoronal attachment is defined as ‘any prefabricated attachment
for support and retention of a removable dental prothesis. The male and
female components are positioned within the normal contour of the abutment
For example: Zest, Ginta, etc.
Some of the commonly used attachments are described below.
• These attachments are of two types – resilient and nonresilient.
• The nonresilient Gerber attachments are the most common and widely
• They consist of male post-threaded into the soldering base and the
female portion consists of female housing consisting of the retention
• All components are interchangeable and replaceable.
• Retention is adequate and fabrication is simple.
• Attachment can torque the tooth, if the denture base has excessive
movement due to poor adaptation.
• A mandrel is needed to parallel the attachments when more than
• It is also known as Puffer and is a spring loaded, vertically resilient
• It allows vertical movement and imparts less torquing forces on the
• It is complex in fabrication and design.
• It has nine parts and is one of the most sophisticated and expensive
• Soldering base is interchangeable.
• Spring-loaded resilience allows the base to adapt under function.
• Torque factor can be considered, if the base is not adapted
• It consists of a soldered base with a removable male stud that is
conical in shape and has a rounded top with an increased diameter
• It splits vertically into four sections.
• These four sections are flexible and are engaged into undersized
• Use of processing spacer allows the attachment to provide vertical
• Overall height of the attachment is 4.5 mm.
• Attachment allows for either solid or resilient fixation.
• Its components are replaceable.
• It requires complex torque-producing intraoral adjustments.
• Nonresilient Ceka can produce excessive torque on the teeth.
• This was originally developed by Carl Axel Gross in 1954 in
• It was introduced in America by Max Zuest in 1973.
• This attachment derives its retention within the root.
• A post preparation is made within the root and the female sleeve is
• Male portion is a nylon post which is placed in the sleeve and is picked
up in the denture resin as a chairside procedure (Fig. 13-5).
• Retention is achieved by the ball head snapping into the undercut of
FIGURE 13-5 Zest anchor attachment.
• It has negligible torque or leverage on the abutment tooth.
• It can be used in reduced interocclusal space.
• It is simple to use and inexpensive.
• Attachment can be used without the dowel or coping.
• It provides slight vertical and rotational movement.
• It can be used on divergent teeth.
• It is susceptible to caries.
• Sleeve requires meticulous oral hygiene maintenance.
• Nylon studs can absorb water and can bend, break or prevent entry
• Studs may be replaced quite frequently.
• This type of attachment can be either resilient or nonresilient (Fig. 13-
• It consists of male stud with a solder core for freehand soldering to a
coping and a female clip consisting of a perforated retention beam
with a split C ring extension.
• Difference in resilient and nonresilient attachment is in the height of
the male portion, i.e. in resilient it is 1.7 mm and in nonresilient it is
FIGURE 13-6 Rothermann attachment.
• Attachment is low in height, it is shortest attachment available.
• It does not require mandrel for alignment and is inexpensive.
• Torque is an absolute minimum.
• Minimal retention can be obtained by spreading the retention ring.
• It has no provision for ‘C’ ring activation.
• There is lingual bulk in the orientation of the attachment.
• When vertical as well as rotational movement is desired (resilient)
• It is a solid cylinder attachment that can be used for fixed removable
bridge work and for overdentures.
• It consists of three parts, namely a solder base, a replaceable and
adjustable male friction part and a female cylindrical housing.
• The male post can be split longitudinally to allow adjustment of the
• Its components are replaceable.
• It can be used in combination with resilient attachments.
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